Liquid crystal (LC) panels have been widely used in display products such as cell phones, smart monitors, LC TV sets, personal computers and so on due to their advantages such as small thinness, high brightness, low radiation and so on.
Usually, the LC panels may have different best voltages at their respective common electrodes since big differences exist among equivalent capacitances of the LC panels. Therefore, when designing a driving circuit of the LC panel, researchers would design a driving circuit with an adjustable resistor. By adjusting the adjustable resistor in the driving circuit, it is possible to realize an adjustment of the voltage at the common electrode such that each LC panel can reach its best voltage at the common electrode. Simultaneously, in order to avoid a flicker phenomenon to exist in pictures displayed on the LC panel, the voltage of the common electrode needs to have a high adjustment precision.
The inventor found that existing voltage adjustment circuits for the common electrode have poor sensitivity and precision in the adjustment, and sometimes cannot adjust the voltage of the common electrode to the most suitable voltage, which affects a display effect of the display apparatus.